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Papers by Bashir M Abubakar
In the last two decades, there has been a tremendous increase in the global use of herbal medicin... more In the last two decades, there has been a tremendous increase in the global use of herbal medicinal products (HMPs) due to their claimed health benefits. This has led to increase in their demand and consequently, also, resulted in massive adulteration. This is due to the fact that most of the traditional methods cannot identify closely related species in a process product form. Therefore the urgent need for simple and rapid identification methods resulted in the discovery of a novel technique. DNA barcoding is a process that uses short DNA sequence from the standard genome for species identification. This technique is reliable and is not affected by external factors such as climates, age, or plant part. The difficulties in isolation of DNA of high quality in addition to other factors are among the challenges encountered using the DNA barcoding in the authentication of HMP. These limitations indicated that using DNA barcoding alone may ineffectively authenticate the HMP. Therefore, the combination of DNA barcoding with chromatographic fingerprint, a popular and generally accepted technique for the assessment and quality control of HMP, will offer an efficient solution to effectively evaluate the authenticity and quality consistency of HMP. Detailed and quality information about the main composition of the HMPs will help to ascertain their efficacy and safety as these are very important for quality control.
Eurycoma longifolia which is known as Tongkat Ali is commonly found in Asian countries such as Ma... more Eurycoma longifolia which is known as Tongkat Ali is commonly found in Asian countries such as Malaysia, Indonesia, Thailand, Myanmar
and Cambodia. This plant is famously known for its various pharmacological activities. The plant is also reported to consist of various types of important bioactive compounds such as quassinoids, canthine-6-one alkaloids, triterpenes, squalene derivatives, $-carboline alkaloids
etc which are mostly found in the root part. The presence of these important phytochemicals contributes to their different types of
therapeutic effects more especially in terms of aphrodisiac properties which have resulted in a massive increase in demand and
production of their Herbal Medicinal Products (HMP). These situations have resulted in the production of E. longifolia HMPs whose quality
are questionable, which might be as a result of restricted of sources that might lead to some unethical activities carried out by suppliers
and manufacturers in order to gain more profit. Therefore, this review focused on adulteration issues such as contamination and
substitution of E. longifolia HMP. The review also includes the possible solutions on how to improve the quality of these HMP so as they
can be safe for consumption. Embracing pharmacovigilance in the preparation of the HMP, proper implementation of agricultural
practices such as Good Agricultural and Collection Practices (GACP) and Good Manufacturing Practices (GMP) together with the
establishment of effective regulatory bodies would undoubtedly improve the quality of E. longifolia HMP sold in the market. The detailed
knowledge about the main composition of the E. longifolia HMP will help to ascertain their quality, efficacy and safety as these are very
important toward quality control.
Biofilm is a community of microorganisms of same or different species encased in a self-produced ... more Biofilm is a community of microorganisms of same or different species encased in a self-produced extracellular polymeric substance on both living and non-living surfaces. Catheters are generally critical indwelling medical devices commonly used in clinical applications to enhanced flow of fluids out of the patient’s body as well as influx of medications into human biological systems. Like many other indwelling medical devices, catheters are prone to enhanced risk of nosocomial infections which becomes a critical challenge as a result of microbial attachment to the surfaces of the catheters. Attachment and subsequent biofilm development on catheter surfaces cause a number of persistent infections. The biofilm development increases resistance to antibiotics. However, this sometimes led to high pathogenesis, patient morbidity and mortality. This condition usually calls for a premature catheter removal which will increase the cost of treatment and improvidence of resources. This review focuses on how catheters get infected, microbial diversity among catheter biofilms, factors mediating biofilm formation on catheters and current strategies used in controlling biofilm formation on indwelling catheters.
Bayero Journal of Pure and Applied Sciences, 2015
An investigation on the occurrence of gastro intestinal helminthes of pigs slaughtered at the Jos... more An investigation on the occurrence of gastro intestinal helminthes of pigs slaughtered at the Jos Abattoir was carried out between May and November 2007, to determined sex, age, and breed related rate of infection, and the possible risk factors to the spread of the epidemic, using direct smear and floatation techniques. Out of the total of 532 examined, 245 (46.10%) were positive for five species of helminthes parasites, namely Taenia solium 44(8.27%) Ascaris suum 52(9.77%), Trichuris suis 40(7.52%) Strongyloids ransomi 16(3.0%) Ascarops strongylina 28(5.26%). Of the 532 pigs sampled, 65(12.22%) were recorded with mixed infection. The parasites were more established in the female pigs 149(50%) than in the male pigs 96(41.02%) However, chi square analysis showed no significant difference in the prevalence rate between female and male pigs (p>0.05). Apparently adult pigs haboured more of the helminthes parasites 240(57.14%) than the young pigs 41(36.61%) although the difference was not statistically significance. The large white breed was infected most, among the various breeds 239(48.28%). The infection rate for the large black was 2(26.67%) and for the mixed breed was 4(20.00%). There was no significant difference in the infection rate among the various breed of pigs (p>0.05). The study shows that breeds and sex are not the promoting factors to infection rate but age.
Biofilm is a co mmunity o f microorganisms of sa me or different species encased in a self-produc... more Biofilm is a co mmunity o f microorganisms of sa me or different species encased in a self-produced extracellular polymeric substance on both living and non-living surfaces. Catheters are generally critical indwelling medical devices commonly used in clinical applications to enhanced flow of flu ids out of the patient's body as well as influ x of medications into human biological systems. Like many other indwelling medical devices, catheters are prone to enhanced risk of nosocomial in fections which becomes a critical challenge as a result of microbial attach ment to the surfaces of the catheters. Attachment and subsequent biofilm development on catheter surfaces cause a number of persistent infections. The biofilm development increases resistance to antibiotics. However, this sometimes led to high pathogenesis, patient morbid ity and mortality. This condition usually calls for a premature catheter removal which will increase the cost of treat ment and improvidence of resources....
Antioxidative compounds play a vital role to inhibit the oxidation of oxidizable products and inf... more Antioxidative compounds play a vital role to inhibit the oxidation of oxidizable products and influences the body defense system against Reactive Oxygen Species (ROS), which are harmful byproducts engendered during normal aerobic cellular respiration. ROS are specialized class of highly reactive molecules that originates during oxygen metabolism, whereas extensive evidences indicate the involvement of ROS in the development of degenerative diseases in humans. Despite the fact that synthetic antioxidants such as butylated hydroxyanisole (BHA) and butylated hydroxytoluene (BHT) are threat to human's health; they are widely employed as chemical preservatives to avert potential deterioration of food products. Several toxicological findings reveal that natural antioxidants are capable of providing protection against free radical-related diseases, cancer and other cardiovascular infections. In cognizance with these facts, natural antioxidant attracts a great deal of research interest; therefore, this review provides a comprehensive and an up-to-date overview of the three most essential natural plant antioxidants; their antioxidative properties, methods of analysis and evaluation. These Polyphenols comprise: Phenolic acid, an essential polyphenol that are broadly dispersed in plants to exert positive influence on oxidative stress; Flavonoid, an ubiquitous antioxidant that functions in free radical scavenging, metal ion chelation and enzymes inhibition to suppress the synthesis of free radicals; and Tannic acid, a water soluble anti-nutrient that acts to precipitate alkaloids & proteins, reduce mineral & vitamin utilization and restrict the activities of digestive enzymes. In conclusion, a variety of plant species were characterized to indicate in vitro antioxidative properties.
Quorum sensing (QS) plays a vital role in controlling virulence in bacterial species. Vibrio chol... more Quorum sensing (QS) plays a vital role in controlling virulence in bacterial species. Vibrio cholerae, the main
causative agent of cholera uses chemical signals to control virulence and biofilm formation. QS Always depend on the
secretion and detection of signaling molecules known as auto inducers. Contrary to other bacteria that cause virulence at High
cell density (HCD) when they attain a specific threshold, reverse is the case for V. Cholerae. At Low cell density (LCD),
activation in the expression of virulence gene by V. cholerae destabilizes HapR while stabilizing AphA. The activation of
AphA structural genes result in the expression of CT and TCP virulence together with the formation of biofilm. At HCD, the
coherence of the two quorum-sensing auto-inducers (CAI-1 and AI-2) represses the expression of the virulence genes by
activating HapR which in turn synthesizes Hap protease that acts as a detachase to get rid of the virulence genes and biofilm
formation. In this review, we outline the QS mechanism used by Vibrio cholerae to cause infection by the production of
virulence factors. In addition, we examine how this infection can be minimize through the use of chemicals which act as
either inhibitors or agonist to the QS system.
Computational Biology and Bioinformatics, 2014
Great advances have been made in the past five decades in understanding the molecular mechanics o... more Great advances have been made in the past five decades in understanding the molecular mechanics of the two-component signal transduction pathway in bacteria but its applications in Medicine and Food Industries are yet to be fully unravelled. We discuss the varying changes in the extracellular environment of bacteria and their possession of multiple Two-Component Systems with each being specialize to react to a specific environmental signal, such as pH, nutrient level, redox state, osmotic pressure, quorum signals, and antibiotics. The sensitivity of this response transmits information between different Two-Component Systems to form a complex signal transduction network. Bacteria's signal transduction system, referred to as a two-component system, are essential for adaptation to external stimuli. These systems provides a signal transduction pathways widely employed from prokaryotes to eukaryotes. Typically, each two-component system composed of a sensor protein distinctively monitors an external signal(s) and a response regulator (RR) that controls gene expression and other physiological activities which are collectively assembled in a signal transduction pathway. This annex reviews the molecular mechanics underlying the signal transduction systems in prokaryotic organisms. It is not uncommon to hear, either explicitly or implicitly, the statement that "two component regulatory systems are well understood". Therefore, we examine the current models of the mechanisms of the regulatory systems and provide viable suggestions to further expand its applications in drug efficiency and antibiotic resistance in humans as well as enhancing the shelf-life of products in the food industry. We also outline the challenges that might have quenched possible trials of this application to human health.
Journal of Materials, 2014
The conversion of waste obtained from agricultural processes into biocompatible materials (biomat... more The conversion of waste obtained from agricultural processes into biocompatible materials (biomaterials) used in medical surgery is a strategy that will add more value in waste utilization. This strategy has successfully turned the rather untransformed wastes into high value products. Eggshell is an agricultural waste largely considered as useless and is discarded mostly because it contributes to pollution. This waste has potential for producing hydroxyapatite, a major component found in bone and teeth. Hydroxyapatite is an excellent material used in bone repair and tissue regeneration. The use of eggshell to generate hydroxyapatite will reduce the pollution effect of the waste and the subsequent conversion of the waste into a highly valuable product. In this paper, we reviewed the utilization of this agricultural waste (eggshell) in producing hydroxyapatite. The process of transforming eggshell into hydroxyapatite and nanohydroxyapatite is an environmentally friendly process. Eggshell based hydroxyapatite and nanohydroxyapatite stand as good chance of reducing the cost of treatment in bone repair or replacement with little impact on the environment.
![Research paper thumbnail of The functional complexity of [NiFe] hydrogenases in sulfate reducing bacteria (genus; Desulforvibrio spp)](https://attachments.academia-assets.com/38375501/thumbnails/1.jpg)
](Sulfate-reducing bacteria are categories of bacteria and archaea that can obtain energy by oxidiz... more Sulfate-reducing bacteria are categories of bacteria and archaea that can obtain energy by oxidizing organic
compounds or molecular hydrogen (H2) while reducing sulfate (SO4
2−) to hydrogen sulfide (H2S). By analysis, these
organisms "respire" sulfate rather than oxygen, a form of anaerobic respiration, the oxidation of hydrogen by the primary
genus of Sulfate Reducing Bacteria (Desulfovibrio, Desulfovibrio desulfuricans) is catalyzed by enzymes called
Hydrogenases. Three basic types of hydrogenases have been widely isolated from the primary genus of sulfate-reducing
bacteria Desulfobibrio which differ in their structural subunits, metal compositions, physico-chemical characteristics,
amino acid sequences, immunological activities, structural gene configuration and their catalytic properties. Broadly,
hydrogenases can be considered as ‘iron containing hydrogenases and nickel-containing hydrogenases. The iron-sulfurcontaining
hydrogenase enzyme contains two ferredoxin-type (4Fe-4S) clusters and typical iron-sulfur center believed to be
involved in the activation of H2 yet it is the most sensitive domain to CO and NO2
−.eventhough it is not featured in all
species of genus Desulfovibrio. The nickel-(iron-sulfur)-containing hydrogenases, [NiFe] hydrogenase posses two 4Fe-4S
centers and one 3Fe-xS cluster in addition to nickel and have been found in all species of Desulfovibrio with strong
resistance to CO and NO2
- so far investigated. The genes encoding the large and small subunits of a periplasmic and
membrane-bound species of the [NiFe] hydrogenase have been cloned in Escherichia coli and sequenced, however the
functional complexity of the hydrogenase system remained unexplored as a result of the metabolic diversity in
Desulfovibrio spp. The [NiFe] hydrogenase plays an important role in the energy metabolism of Desulfovibrio spp. Thus,
the expression of the encoded structural genes would be an excellent marker for the metabolic functionalities under specific
inducible environment.
In the last two decades, there has been a tremendous increase in the global use of herbal medicin... more In the last two decades, there has been a tremendous increase in the global use of herbal medicinal products (HMPs) due to their claimed health benefits. This has led to increase in their demand and consequently, also, resulted in massive adulteration. This is due to the fact that most of the traditional methods cannot identify closely related species in a process product form. Therefore the urgent need for simple and rapid identification methods resulted in the discovery of a novel technique. DNA barcoding is a process that uses short DNA sequence from the standard genome for species identification. This technique is reliable and is not affected by external factors such as climates, age, or plant part. The difficulties in isolation of DNA of high quality in addition to other factors are among the challenges encountered using the DNA barcoding in the authentication of HMP. These limitations indicated that using DNA barcoding alone may ineffectively authenticate the HMP. Therefore, the combination of DNA barcoding with chromatographic fingerprint, a popular and generally accepted technique for the assessment and quality control of HMP, will offer an efficient solution to effectively evaluate the authenticity and quality consistency of HMP. Detailed and quality information about the main composition of the HMPs will help to ascertain their efficacy and safety as these are very important for quality control.
Eurycoma longifolia which is known as Tongkat Ali is commonly found in Asian countries such as Ma... more Eurycoma longifolia which is known as Tongkat Ali is commonly found in Asian countries such as Malaysia, Indonesia, Thailand, Myanmar
and Cambodia. This plant is famously known for its various pharmacological activities. The plant is also reported to consist of various types of important bioactive compounds such as quassinoids, canthine-6-one alkaloids, triterpenes, squalene derivatives, $-carboline alkaloids
etc which are mostly found in the root part. The presence of these important phytochemicals contributes to their different types of
therapeutic effects more especially in terms of aphrodisiac properties which have resulted in a massive increase in demand and
production of their Herbal Medicinal Products (HMP). These situations have resulted in the production of E. longifolia HMPs whose quality
are questionable, which might be as a result of restricted of sources that might lead to some unethical activities carried out by suppliers
and manufacturers in order to gain more profit. Therefore, this review focused on adulteration issues such as contamination and
substitution of E. longifolia HMP. The review also includes the possible solutions on how to improve the quality of these HMP so as they
can be safe for consumption. Embracing pharmacovigilance in the preparation of the HMP, proper implementation of agricultural
practices such as Good Agricultural and Collection Practices (GACP) and Good Manufacturing Practices (GMP) together with the
establishment of effective regulatory bodies would undoubtedly improve the quality of E. longifolia HMP sold in the market. The detailed
knowledge about the main composition of the E. longifolia HMP will help to ascertain their quality, efficacy and safety as these are very
important toward quality control.
Biofilm is a community of microorganisms of same or different species encased in a self-produced ... more Biofilm is a community of microorganisms of same or different species encased in a self-produced extracellular polymeric substance on both living and non-living surfaces. Catheters are generally critical indwelling medical devices commonly used in clinical applications to enhanced flow of fluids out of the patient’s body as well as influx of medications into human biological systems. Like many other indwelling medical devices, catheters are prone to enhanced risk of nosocomial infections which becomes a critical challenge as a result of microbial attachment to the surfaces of the catheters. Attachment and subsequent biofilm development on catheter surfaces cause a number of persistent infections. The biofilm development increases resistance to antibiotics. However, this sometimes led to high pathogenesis, patient morbidity and mortality. This condition usually calls for a premature catheter removal which will increase the cost of treatment and improvidence of resources. This review focuses on how catheters get infected, microbial diversity among catheter biofilms, factors mediating biofilm formation on catheters and current strategies used in controlling biofilm formation on indwelling catheters.
Bayero Journal of Pure and Applied Sciences, 2015
An investigation on the occurrence of gastro intestinal helminthes of pigs slaughtered at the Jos... more An investigation on the occurrence of gastro intestinal helminthes of pigs slaughtered at the Jos Abattoir was carried out between May and November 2007, to determined sex, age, and breed related rate of infection, and the possible risk factors to the spread of the epidemic, using direct smear and floatation techniques. Out of the total of 532 examined, 245 (46.10%) were positive for five species of helminthes parasites, namely Taenia solium 44(8.27%) Ascaris suum 52(9.77%), Trichuris suis 40(7.52%) Strongyloids ransomi 16(3.0%) Ascarops strongylina 28(5.26%). Of the 532 pigs sampled, 65(12.22%) were recorded with mixed infection. The parasites were more established in the female pigs 149(50%) than in the male pigs 96(41.02%) However, chi square analysis showed no significant difference in the prevalence rate between female and male pigs (p>0.05). Apparently adult pigs haboured more of the helminthes parasites 240(57.14%) than the young pigs 41(36.61%) although the difference was not statistically significance. The large white breed was infected most, among the various breeds 239(48.28%). The infection rate for the large black was 2(26.67%) and for the mixed breed was 4(20.00%). There was no significant difference in the infection rate among the various breed of pigs (p>0.05). The study shows that breeds and sex are not the promoting factors to infection rate but age.
Biofilm is a co mmunity o f microorganisms of sa me or different species encased in a self-produc... more Biofilm is a co mmunity o f microorganisms of sa me or different species encased in a self-produced extracellular polymeric substance on both living and non-living surfaces. Catheters are generally critical indwelling medical devices commonly used in clinical applications to enhanced flow of flu ids out of the patient's body as well as influ x of medications into human biological systems. Like many other indwelling medical devices, catheters are prone to enhanced risk of nosocomial in fections which becomes a critical challenge as a result of microbial attach ment to the surfaces of the catheters. Attachment and subsequent biofilm development on catheter surfaces cause a number of persistent infections. The biofilm development increases resistance to antibiotics. However, this sometimes led to high pathogenesis, patient morbid ity and mortality. This condition usually calls for a premature catheter removal which will increase the cost of treat ment and improvidence of resources....
Antioxidative compounds play a vital role to inhibit the oxidation of oxidizable products and inf... more Antioxidative compounds play a vital role to inhibit the oxidation of oxidizable products and influences the body defense system against Reactive Oxygen Species (ROS), which are harmful byproducts engendered during normal aerobic cellular respiration. ROS are specialized class of highly reactive molecules that originates during oxygen metabolism, whereas extensive evidences indicate the involvement of ROS in the development of degenerative diseases in humans. Despite the fact that synthetic antioxidants such as butylated hydroxyanisole (BHA) and butylated hydroxytoluene (BHT) are threat to human's health; they are widely employed as chemical preservatives to avert potential deterioration of food products. Several toxicological findings reveal that natural antioxidants are capable of providing protection against free radical-related diseases, cancer and other cardiovascular infections. In cognizance with these facts, natural antioxidant attracts a great deal of research interest; therefore, this review provides a comprehensive and an up-to-date overview of the three most essential natural plant antioxidants; their antioxidative properties, methods of analysis and evaluation. These Polyphenols comprise: Phenolic acid, an essential polyphenol that are broadly dispersed in plants to exert positive influence on oxidative stress; Flavonoid, an ubiquitous antioxidant that functions in free radical scavenging, metal ion chelation and enzymes inhibition to suppress the synthesis of free radicals; and Tannic acid, a water soluble anti-nutrient that acts to precipitate alkaloids & proteins, reduce mineral & vitamin utilization and restrict the activities of digestive enzymes. In conclusion, a variety of plant species were characterized to indicate in vitro antioxidative properties.
Quorum sensing (QS) plays a vital role in controlling virulence in bacterial species. Vibrio chol... more Quorum sensing (QS) plays a vital role in controlling virulence in bacterial species. Vibrio cholerae, the main
causative agent of cholera uses chemical signals to control virulence and biofilm formation. QS Always depend on the
secretion and detection of signaling molecules known as auto inducers. Contrary to other bacteria that cause virulence at High
cell density (HCD) when they attain a specific threshold, reverse is the case for V. Cholerae. At Low cell density (LCD),
activation in the expression of virulence gene by V. cholerae destabilizes HapR while stabilizing AphA. The activation of
AphA structural genes result in the expression of CT and TCP virulence together with the formation of biofilm. At HCD, the
coherence of the two quorum-sensing auto-inducers (CAI-1 and AI-2) represses the expression of the virulence genes by
activating HapR which in turn synthesizes Hap protease that acts as a detachase to get rid of the virulence genes and biofilm
formation. In this review, we outline the QS mechanism used by Vibrio cholerae to cause infection by the production of
virulence factors. In addition, we examine how this infection can be minimize through the use of chemicals which act as
either inhibitors or agonist to the QS system.
Computational Biology and Bioinformatics, 2014
Great advances have been made in the past five decades in understanding the molecular mechanics o... more Great advances have been made in the past five decades in understanding the molecular mechanics of the two-component signal transduction pathway in bacteria but its applications in Medicine and Food Industries are yet to be fully unravelled. We discuss the varying changes in the extracellular environment of bacteria and their possession of multiple Two-Component Systems with each being specialize to react to a specific environmental signal, such as pH, nutrient level, redox state, osmotic pressure, quorum signals, and antibiotics. The sensitivity of this response transmits information between different Two-Component Systems to form a complex signal transduction network. Bacteria's signal transduction system, referred to as a two-component system, are essential for adaptation to external stimuli. These systems provides a signal transduction pathways widely employed from prokaryotes to eukaryotes. Typically, each two-component system composed of a sensor protein distinctively monitors an external signal(s) and a response regulator (RR) that controls gene expression and other physiological activities which are collectively assembled in a signal transduction pathway. This annex reviews the molecular mechanics underlying the signal transduction systems in prokaryotic organisms. It is not uncommon to hear, either explicitly or implicitly, the statement that "two component regulatory systems are well understood". Therefore, we examine the current models of the mechanisms of the regulatory systems and provide viable suggestions to further expand its applications in drug efficiency and antibiotic resistance in humans as well as enhancing the shelf-life of products in the food industry. We also outline the challenges that might have quenched possible trials of this application to human health.
Journal of Materials, 2014
The conversion of waste obtained from agricultural processes into biocompatible materials (biomat... more The conversion of waste obtained from agricultural processes into biocompatible materials (biomaterials) used in medical surgery is a strategy that will add more value in waste utilization. This strategy has successfully turned the rather untransformed wastes into high value products. Eggshell is an agricultural waste largely considered as useless and is discarded mostly because it contributes to pollution. This waste has potential for producing hydroxyapatite, a major component found in bone and teeth. Hydroxyapatite is an excellent material used in bone repair and tissue regeneration. The use of eggshell to generate hydroxyapatite will reduce the pollution effect of the waste and the subsequent conversion of the waste into a highly valuable product. In this paper, we reviewed the utilization of this agricultural waste (eggshell) in producing hydroxyapatite. The process of transforming eggshell into hydroxyapatite and nanohydroxyapatite is an environmentally friendly process. Eggshell based hydroxyapatite and nanohydroxyapatite stand as good chance of reducing the cost of treatment in bone repair or replacement with little impact on the environment.
Sulfate-reducing bacteria are categories of bacteria and archaea that can obtain energy by oxidiz... more Sulfate-reducing bacteria are categories of bacteria and archaea that can obtain energy by oxidizing organic
compounds or molecular hydrogen (H2) while reducing sulfate (SO4
2−) to hydrogen sulfide (H2S). By analysis, these
organisms "respire" sulfate rather than oxygen, a form of anaerobic respiration, the oxidation of hydrogen by the primary
genus of Sulfate Reducing Bacteria (Desulfovibrio, Desulfovibrio desulfuricans) is catalyzed by enzymes called
Hydrogenases. Three basic types of hydrogenases have been widely isolated from the primary genus of sulfate-reducing
bacteria Desulfobibrio which differ in their structural subunits, metal compositions, physico-chemical characteristics,
amino acid sequences, immunological activities, structural gene configuration and their catalytic properties. Broadly,
hydrogenases can be considered as ‘iron containing hydrogenases and nickel-containing hydrogenases. The iron-sulfurcontaining
hydrogenase enzyme contains two ferredoxin-type (4Fe-4S) clusters and typical iron-sulfur center believed to be
involved in the activation of H2 yet it is the most sensitive domain to CO and NO2
−.eventhough it is not featured in all
species of genus Desulfovibrio. The nickel-(iron-sulfur)-containing hydrogenases, [NiFe] hydrogenase posses two 4Fe-4S
centers and one 3Fe-xS cluster in addition to nickel and have been found in all species of Desulfovibrio with strong
resistance to CO and NO2
- so far investigated. The genes encoding the large and small subunits of a periplasmic and
membrane-bound species of the [NiFe] hydrogenase have been cloned in Escherichia coli and sequenced, however the
functional complexity of the hydrogenase system remained unexplored as a result of the metabolic diversity in
Desulfovibrio spp. The [NiFe] hydrogenase plays an important role in the energy metabolism of Desulfovibrio spp. Thus,
the expression of the encoded structural genes would be an excellent marker for the metabolic functionalities under specific
inducible environment.